Field of the Invention
The present invention relates generally to an improvement in mailing machines and, more particularly, to an envelope deskewing device for a mailing machine which prints postage indicia in a predetermined location on envelopes.
Mailing machines are well known in the prior art and are found in post offices and in mailrooms of companies and business offices the world over. Typically, a mailing machine comprises a feed base having an elongate deck which presents a flat surface on which envelopes can be fed one at a time and a feeding mechanism for feeding the envelopes. Mailing machines may be either hand fed, in which case an operator places a single envelope on the feed deck and slides it into engagement with the feeding mechanism, or automatically fed wherein envelopes are fed seriatim from a stack held in a suitable hopper and transferred across the feed deck.
The mailing machine also includes a postage meter which, with a few exceptions, is removably connected to the feed base. The postage meter, as is well known, is basically a printing device which prints a particular type of postage indicia on the envelope adjacent the upper right hand corner, the printed postage indicia serving in lieu of a postage stamp as proof of payment of the postage charge. Typically, the postage meter has settable printing wheels to facilitate selecting different amounts of postage and dates to be printed, and there are suitable mechanical or electronic means for setting the printing wheels and for keeping track of the amount of postage printed for accounting and security purposes.
The present invention is particularly useful in the hand fed type of mailing machine, but may also be utilized to advantage in automatic mailing machines. In either case, envelopes must be fed through the mailing machine in proper alignment with the printing drum of the postage meter in order to have the postage indicia printed in a precise location and orientation on the envelopes. It is important that the postage indicia be printed in a precise location and orientation in order to assure that there is no loss of any portion on the postage indicia, which would violate federal regulations covering metered mail, and also to assure that there is no loss of the customer's advertising slogan and/or design which may be printed by the meter which would offend the customer. These malfunctions are made possible by the typical mailing machine design. The postage meter is triggered by the lead edge of the envelope striking a trip actuator or energizing an electronic receiving device to signal the arrival of the envelope at a known location. If the envelope is moving through the mailing machine in a skewed relationship, the portion of the envelope which triggers the operation of the postage meter will not be in the proper location when it engages the triggering device, thereby actuating the postage meter either too soon or too late.
Another reason for the importance of feeding the envelopes through the mailing machine in proper registration with the printing drum is to avoid damage to the envelope in other portions of the mailing machine. Typically, mailing machines are provided with a moistening and sealing device upstream from the printing drum of the postage meter. If an envelope is fed through the moistening component in other than a substantially properly aligned orientation, there is a high probability that the flap of the envelope will catch and tear on the moistening component and the envelope will not be properly sealed. It is also quite possible that the tearing of the flap could cause the envelope to jam in the mailing machine and cause a complete malfunction.
After recognizing the importance of providing a deskewing device in a mail handling machine for any one or more of the reasons mentioned above, it was discovered that there is a limitation to the amount of misregistration with which an envelope can be placed on the feed table and still have it become properly registered by the deskewing device before the envelope reaches the printing drum of the postage meter. Prior means have been developed for deskewing a envelope, particularly U.S. patent application Ser. No. 808,198, entitled "Deskewing Device For Mailing Machine", filed Dec. 12, 1984 and assigned to Pitney Bowes, Inc. However, the deskewing device described in the cited application has an expressed entry angle limitation, i.e., the device will properly align an envelope relative to the register provided the angle of entry to the deskewing devices does not exceed 12 degrees.